Abstract
BACKGROUND: Auditory verbal hallucinations (AVHs) are common and distressing symptoms across a range of psychiatric disorders, including schizophrenia spectrum disorders. Audio Visual Assisted Therapy Aid for Refractory Auditory Hallucinations (AVATAR) is an innovative therapeutic approach that facilitates dialogue with a digital avatar representing the voices that patients hear. AIMS: This systematic review and meta-analysis aimed to assess the efficacy, tolerability and acceptability of AVATAR therapy in reducing voice-related symptoms. METHOD: Following preregistration, we conducted a systematic review and meta-analysis of controlled trials of AVATAR therapy in samples primarily diagnosed with schizophrenia spectrum disorders. PubMed, CINAHL, Embase, PsycInfo, ClinicalTrials.gov, ISRCTN and Web of Science were searched in March 2025. We assessed bias and certainty with the Cochrane Risk-of-Bias 2 tool and the GRADE approach. Random-effects models were used to synthesise outcomes. RESULTS: Eight AVATAR trials (N = 978) were included. Compared with usual treatment, waitlist and active control groups, AVATAR therapy decreased the primary outcome of AVH severity at post-treatment (Hedges' g = -0.40, 95% CI -0.54 to -0.25) and short-term follow-up (Hedges' g = -0.25, 95% CI -0.40 to -0.10). AVH subscales showed small significant effect sizes at post-treatment (frequency: Hedges' g = -0.38, 95% CI -0.52 to -0.24; distress: Hedges' g = -0.32, 95% CI -0.46 to -0.18), which were maintained at short-term follow-up. The certainty of evidence was rated moderate for AVH severity at post-treatment. AVATAR therapy was largely tolerable and acceptable, with adverse events mostly unrelated to the treatment and a comparable drop-out rate to control groups. CONCLUSIONS: Findings suggest that AVATAR therapy is effective at reducing AVH symptoms. Considering heterogeneous control groups and less clear evidence for secondary outcomes and longer follow-ups, further research is warranted.